1. Field of the Invention
The present invention relates to methods and apparatus for producing holes in the walls of tubes, such as producing laterally projecting holes in polymeric tubular stock in the manufacture of catheters used in radiographic procedures for diagnosing coronary or other arterial disease.
2. Description of the Prior Art
In the prior art, holes are formed in the walls of tubular catheter stock by using a tubular punch held in a pin vice or hand chuck to enable the tubular punch to be positioned and engaged with the wall of the tubular stock with a twisting and pushing motion to sever a circular portion of the wall and form a hole. Where a plurality of holes are formed within a catheter, each hole is individually formed. The prior art procedures were costly since they required considerable manpower. Also in the prior art, optimum and uniform placement of holes is difficult to obtain, and there is a substantial risk of forming burrs which could traumatize blood vessels, and of forming loose cut material which could be later dislodged and discharged into a blood vessel.